Add life rules and implement tests for civilization and life states

- Introduced a new file `life_rules.txt` to define life progression and degradation rules.
- Created `test_civilization_state.gd` to validate the functionality of civilization rules and ethics.
- Added `test_life.gd` to test life evolution, including initialization, batch processing, and state validation.
- Implemented `civilization_state.gd` to manage civilization ethics and space civilization detachment logic.
- Ensured all tests check for expected outcomes and validate state integrity after operations.

world/owniverse/civilization_state.gd

@@ -0,0 +1,36 @@
+extends RefCounted
+
+const ETHICS = ["m", "l", "w", "d", "c", "b"]
+
+static func is_space_civilization(id: String, rules: Dictionary) -> bool:
+    return rules.has(id) and str(rules[id].home) != ""
+
+# Preserve any existing ethics. New populations start equally distributed;
+# reductions (including blasts) are proportional and never leave negative counts.
+static func reconcile(world, target: Dictionary, rules: Dictionary) -> void:
+    if not target.has("ethics"):
+        target.ethics = {}
+    var physical: Dictionary = world._physical_amounts(target)
+    for id in rules:
+        var count: float = physical.get(id, 0.0)
+        var current: Dictionary = target.ethics.get(id, {})
+        var total: float = 0.0
+        for ethic in ETHICS:
+            current[ethic] = maxf(0.0, current.get(ethic, 0.0))
+            total += current[ethic]
+        if total > count:
+            current = world._allocate_whole(current, count)
+        elif total < count:
+            var missing: float = count - total
+            var base: float = floorf(missing / ETHICS.size())
+            var rest: int = int(missing - base * ETHICS.size())
+            for i in ETHICS.size():
+                current[ETHICS[i]] += base + (1.0 if i < rest else 0.0)
+        target.ethics[id] = current
+
+static func detach_space_civilizations(target: Dictionary, rules: Dictionary) -> void:
+    for held: Dictionary in target.binds.values():
+        for id in held:
+            if is_space_civilization(id, rules):
+                target.amount[id] = target.amount.get(id, 0.0) + held[id]
+                held[id] = 0.0